The effect of Mg add on morphology and mechanical properties of Al-xMg/10Al2O3 nanocomposite produced by mechanical alloying

Effect of Mg content on microstructure and mechanical properties of Al-xMg/10 wt.%Al2O3 (x = 0, 5, 10 and 15 wt.%) powder mixtures during milling was investigated. The results show that for the binary Al-Mg matrix, the predominant phase was an Al-Mg solid solution. With the increment of Mg to 15 wt.% the crystallite sizes of 20 h milled powders diminish from 44 to 26 nm and lattice strains increased from 0.22% to 0.32% caused by Mg atomic penetration into the substitution sites of the Al lattice. With up to 15 wt.% Mg (for 20 h milled composites) microhardness increases from 120 to 230 HV caused by the increment of the Mg concentration and dislocation density as well as the decrease of the crystallite size.